Off-label use of targeted therapies in osteosarcomas: data from the French registry OUTC'S (Observatoire de l'Utilisation des Thérapies Ciblées dans les Sarcomes):

BACKGROUND: The objective of this study is to explore the off-label use of targeted therapies (TTs) for patients with osteosarcoma registered within the French Sarcoma Group--Bone Tumor Study Group (GSF-GETO) national registry. METHODS: All patients with an osteosarcoma, registered between January 1, 2009 and July 15, 2013 were analyzed. RESULTS: Twenty-nine patients with refractory relapsed osteosarcomas received 33 treatment lines of TTs. The median age at the beginning of treatment was 19 years (range 9-72). The median number of previous lines of chemotherapy was 3 (range 1-8). Before inclusion, 3 patients were in second complete remission, 26 were in progression for metastatic relapse. Twenty-three patients received sirolimus (in combination with cyclophosphamide for 18); 5, sunitinib; 4, sorafenib; and one, pazopanib. Stable disease was observed for 45.5% of patients (95% Confidence Interval (CI) [20-52.8]). The median Progression-Free Survival (PFS) was 3 months (95% CI [2-5.4]) for patients treated by sirolimus and 1.8 months (95% CI [1.3-2.8]) for patients receiving multi-targeted tyrosine kinase inhibitors; 6-month PFS 15%. The median Overall Survival (OS) was 6.8 months (95% CI [4.7-12.1]), and one-year OS was 24%. In a multivariate analysis, PFS was superior for patients receiving sirolimus compared to other TTs (Hazard Ratio (HR) = 2.7, 95% CI [1.05-7.1]). No toxic death was reported. Grade 3 and 4 toxicities were observed in 27 and 6% of cases respectively. CONCLUSION: Off-label TTs, especially sirolimus, reported benefit in the treatment of refractory osteosarcomas with an acceptable toxicity profile, including in pediatric population

Differential diagnosis of neonatal alloimmune thrombocytopenia: Type 2B von Willebrand disease

At birth, severe thrombocytopenia without context of infection should mainly suggest neonatal alloimmune thrombocytopenia (NAIT), especially in case of a platelet count below 20 GL−1. We report two cases of severe neonatal thrombocytopenia, first suspected as being NAIT. Both had a platelet count below 20 GL−1 with platelet clumps. The absence of alloantibodies and failure of platelet transfusion and intravenous immunoglobulins to improve the platelet count led to question the diagnosis and to evoke inherited bleeding disorders. Measurements of Von Willebrand factor (VWF) levels showed a marked reduction of VWF:RCo and a normal VWF:Ag, suggesting a type 2B Von Willebrand disease (VWD2B). Ristocetin-induced platelet aggregation could not be performed because of the very low platelet count. In the first case, after sequencing VWF exon 28, a heterozygous p.Leu1460Pro mutation was found consistent with VWD2B. In the second case, the genetic analysis of VWF exon 28 identified a homozygous mutation: p.Pro1337Leu confirming type VWD2B and also the p.Arg854Gln homozygous mutation in exon 20 confirming type 2N (ratio FVIII/VWF:Ag <0.5). The two cases underline that, even if NAIT remains the most common diagnosis in severe neonatal thrombocytopenia, it should be challenged in the absence of documented incompatibility, chronic evolution, or treatment failure. Diagnosis of VWD2B should be considered in early thrombocytopenia, even without familial history. In the cases presented, genotyping confirmed the subtype of VWD and helped to guide the therapeutic management of bleeding episodes

Management of Febrile Neutropenias in Adolescents and Young Adults: A Cost-Minimization Analysis Between Adult Versus Pediatric Units

International audienc

Management of Febrile Neutropenias in Adolescents and Young Adults: A Cost-Minimization Analysis Between Adult Versus Pediatric Units

International audienc

Interest of the preventive and curative use of defibrotide on the occurrence and severity of sinusoidal obstruction syndrome after hematopoietic stem cell transplant in children

Abstract Defibrotide (DF) is indicated for the treatment of severe sinusoidal obstruction syndrome (SOS) following hematopoietic stem cell transplantation (HSCT), but its prophylactic use against SOS is not recommended yet. This study describes the impact of the preventive and curative use of DF on reducing the incidence and severity of SOS in children. Patients aged 0–19 years, who received allogenic HSCT after myeloablative conditioning regimen with busulfan or total body irradiation in our comprehensive cancer center, between 2013 and 2017, were included. The Baltimore or modified Seattle criteria were used for SOS diagnosis. SOS was graded using the 2017 European Society for Blood and Marrow Transplantation classification defining severity criteria of SOS in children. SOS occurrence tended to decrease with prophylactic DF, but no significant difference was observed in terms of severity. When not treated with preventive DF, 50% (19/38) of the patients with SOS were graded severe to very severe, but only 37% (7/19) had organ dysfunction. Curative DF was administered at a median of 2 days post‐HSCT, for a median of 6.5 days. The absence of fatal SOS supports the use of early curative DF with acceptable toxicities and questions the optimal duration of DF treatment

Treatment with cyclosporin in auto-immune cytopenias in children: The experience from the French cohort OBS'CEREVANCE

International audienc

Familial Mediterranean fever mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome

Objectives. FMF is the most frequent autoinflammatory disease and is associated in most patients with bi-allelic MEFV mutations. MEFV encodes Pyrin, an inflammasome sensor activated following RhoGTPase inhibition. The functional consequences of MEFV mutations on the ability of Pyrin variants to act as inflammasome sensors are largely unknown. The aim of this study was to assess whether MEFV mutations affect the ability of Pyrin to detect RhoGTPase inhibition and other inflammasome stimuli. Methods. IL-1β and IL-18 released by monocytes from healthy donors (HDs) and FMF patients were measured upon specific engagement of the Pyrin, NLRP3 and NLRC4 inflammasomes. Cell death kinetics following Pyrin activation was monitored in real time. Results. Monocytes from FMF patients secreted significantly more IL-1β and IL-18 and died significantly faster than HD monocytes in response to low concentrations of Clostridium difficile toxin B (TcdB), a Pyrin-activating stimulus. Monocytes from patients bearing two MEFV exon 10 pathogenic variants displayed an increased Pyrin inflammasome response compared with monocytes from patients with a single exon 10 pathogenic variant indicating a gene-dosage effect. Using a short priming step, the response of monocytes from FMF patients to NLRP3-and NLRC4-activating stimuli was normal indicating that MEFV mutations trigger a specific hypersensitivity of monocytes to low doses of a Pyrin-engaging stimulus. Conclusion. Contrary to the NLRP3 mutations described in cryopyrin-associated periodic syndrome, FMF-associated MEFV mutations do not lead to a constitutive activation of Pyrin. Rather, FMF-associated mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome without affecting other canonical inflammasomes